Introduction to Float Switches
A float switch is a simple yet highly reliable device used to detect the level of liquid in a tank, sump, or reservoir. By opening or closing an electrical circuit in response to rising or falling fluid levels, float switches are widely used to start or stop pumps, trigger alarms, or control valves.
In industries such as water treatment, wastewater management, and building services, float switches are essential for ensuring smooth and efficient pumping operations. Improper level control can result in pump damage, costly downtime, or even environmental hazards due to overflow.
How Does a Float Switch Work?
The working principle of a float switch is straightforward:
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As the liquid level rises to a pre-set point, the float tilts or lifts.
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This action activates an internal microswitch, which sends a signal to start the pump.
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Once the liquid is drained and the float returns to its vertical position, the switch signals the pump to stop.
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The cycle repeats whenever liquid levels fluctuate.
In multi-pump stations, multiple float switches are installed at different heights – one for each pump’s start level, one for stop, and another to trigger a high-level alarm.
Applications of Float Switches
Float switches are versatile and used across a broad range of applications, including:
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Wastewater pumping stations – reliable liquid level control in sewage and drainage systems.
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Groundwater and stormwater management – effective monitoring during heavy rainfall.
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Water tanks and reservoirs – ensuring automatic start and stop of booster or transfer pumps.
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Industrial processes – controlling levels of chemicals, oils, or process water.
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Marine and offshore – bilge water level detection in ships and platforms.
Key Benefits of Using Float Switches
1. Simplicity and Reliability
The Flygt ENM-10 float switch (liquid level regulator) is a proven solution with more than a decade of successful installations worldwide. Its robust design ensures accurate liquid level detection even under harsh operating conditions.
2. Practically Maintenance-Free
Unlike surface-floating designs, the ENM-10 hangs immersed in liquid, preventing cable tangling and minimising build-up of impurities. Xylem’s testing shows it lasts significantly longer than standard regulators, reducing servicing costs.
3. Environmentally Friendly
The ENM-10 contains no harmful materials such as lead or mercury. All components are welded or screwed together, eliminating the need for adhesives.
4. Durability and Resistance
With a polypropylene body and watertight cable, the ENM-10 withstands aggressive liquids and delivers dependable performance in demanding environments.
Technical Features of the Flygt ENM-10 Float Switch
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Ingress protection: IP68 – fully submersible and protected against water ingress.
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Electrical range: up to 250V AC / 10A resistive load.
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Temperature range: 0°C to 60°C.
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Cable lengths: available in 6, 13, 20, 30, or 50 metres.
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Microswitch reliability: ensures accurate operation, even with slow fluid movement.
Choosing the Right Float Switch
When selecting a float switch, consider:
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Liquid type (clean water, wastewater, chemicals).
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Density and temperature of the medium.
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Installation environment (domestic, commercial, industrial, or hazardous zones).
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Required approvals such as CE or ATEX (for explosive environments).
The Flygt ENM-10 is available in both standard and Ex-approved versions, making it suitable for a wide range of industries.
Conclusion
A float switch is one of the most cost-effective and reliable solutions for liquid level control. By ensuring pumps start and stop automatically, they protect systems, reduce energy wastage, and safeguard against environmental hazards.
At Winston Engineering, we supply and install float switches such as the Flygt ENM-10, trusted by industries worldwide for durability, efficiency, and safety.
📩 For enquiries, contact us at [email protected] or visit winstonengineering.com.
